With the problem of engine, you must not drive the car. Due to the problem of the car engine, you may face fetal accident what will be uncured. That is why, whenever you have found the car engine problem, you should test the car engine as soon as possible if you think to drive the car safely. Testing the car engine by the engine code reader lets you know about the engine code and the engine P1645 Code is found for the test. Now by the meaning of this engine code, you can find the engine problem what you need to fix.